Gerasimov told reporters that the scale-down of Russian troops could start before the end of the year.

On Wednesday, Russian President Vladimir Putin hosted the leaders of Turkey and Iran in Sochi, where they discussed the terms of a ceasefire agreement in Syria as well as the political future of its President, Bashar al-Assad.

"Thanks to the efforts made by the Russian army, Iran and Turkey, Syria has been saved," Putin said on the sidelines of his meeting with Iran's President Hassan Rouhani and Turkey's President Recep Tayyip Erdoğan.